Improvement in lifting-jacks



cago, in the county tml@ ' PATENT @Trice EMERY GARD, OF CHICAGO,ILLINOIS.

IMPROVEMENT IN LIFTING-JACKS.

Specification forming part of Letters Patent No. 116,296, dated June 27,1871.

To all whom it may conc-em:

Be it known that I, EMERY R. GARD, of Chiof Cook and State of Illinois,have invented an Improved Lifting-Jack; and I do hereby declare that thefollowing is a full and eXact description thereof, reference being hadto the accompanying drawing making part of this speciiication- Figure lbeing a side elevation of the jack arranged for raising` heavy weights;Fig. 2, a side lelevation of the same arranged for lowering weights;Fig. 3, an elevation of the jack arranged as 'in Fig. 2 and taken atright angles to that view; Fig. 4, a side elevation of the body orstandard of the jack, provided with an additional base for more fullyadjusting the height of the jack to snit weights situated at variousheights; Fig. 5, an elevation of the same taken at right angles to theview in Fig. 4.

Like letters designate corresponding parts in all of the figures.

A represents the base and standard of the jack 5 B, the lifting-bar,moving up and down vertically in the standard as a socket therefor 5 andC, the pawl-lever pivoted to the top of the standard. The lifting-bar Bhas two sets of ratchet-teeth, one on each opposite edge, so vthat eachvibration of the pawl-lever acts upon it to lift it.

This jack is -intended to be perfectly adapted to lifting heavy weightsslowly and light weights more rapidly; and, iirst, to this effect it hastwo pairs of lifting-pawls on the pawl-lever, one pair, D D, with itspivots a a at a comparatively great distance from the fulcrum of thelever, so as to move a greater distance with a given eX- tent of thelevers motion, and thus reach past two or three ofthe ratchet-teeth atonce; and the other pair, E E, having its pivots b Z) comparatively nearthe fulcrum of the lever, so as to reach only a single ratchet-tooth ateach vibration of the lever, and thereby lift slowly but with greaterlever-age. Second, the lever@` is made with a single permanent handle,c, to be used alone when lifting comparatively light weights, and at theother end has a handle-socket, in which to place another handle, d,shown by dotted lines in Figs. 1 and 2, for an additional person orpersons to work with in lifting very heavy weights; this additionallever being removable, so as not to encumber the jack when not needed tobe used. The upper pawls D D, for lifting light weights, are

thrown back upon-the lever, as shown in the drawing', when the lowersuspended -pawls E E are in action for raising heavy weights. Thesuspended pawlstdo not interfere with the action of the upper pawls,even when remaining 1n gear.

An important feature of this invention is a device for lowering weightsautomatically by the same action ofthe lever and pawls as when raisingweights, the construction, arrangement, and operation thereof beingsubstantiallyr as follows: On the two opposite sides of the standard Aswung in to different positions. Their upper ends are curvedsubstantially as shown, or otherwise formed so as to eiiect the purposedesired, and their lower ends are weighted, so vas to hold the upperends steadily in position for the suspended pawls E E, which projectlaterally over the guides, to slide on without disturbing them when thedevice is in action. These guides, when not in use, are swung up intothe position shown in Fig. l, and are held there by a sliding band, H,(or its equivalent,) on'the stock of the standard A, this band catchinginto a notch, f, in the edgeof one ofthe guides, as shown. When theguides are to be brought into action, the one having the notch fislifted a little to disengage the slide H, which dropslor slides on thestandard till it reaches and rest-s on stops g g on the standard, asseen in Fig. 2. The guides then swing down by their own gray'ity intothe position shown in Fig. 2, being held there in the exact positionsrequired by stops h h thereon striking the sides of the standard. Theupper ends of the guides in this position are such as to throw the pawlsE E sliding thereon successively out of gear with the teeth of theratchet-bar B in descendn g, as indicated at the left hand in Fig. 2,but not to prevent the aseen ding pawl from' taking into the next higherratchet-tooth, as indicated at the right hand in the same figure. Theeffect is to lower the lifting-bar by the ordinary action of the lever,a great desideratum in lifting-jacks.

In order to give greater range to the lifting height of the jack, anauxiliary base, I, is employed, as shown in Figs. 4 and 5. This is asocket, in which the standard A slides up and down. There .isprperly ahole in the lower end of the standard, through which a pin or bolt, z',is inserted, and there is a set of holes, l l, in opposite areV pivotedtwo guides, G G, so that they can bed/A sides of the auxiliarybase,through different ones oi' which the bolt I is inserted to vary theheight of the standards.

lVhat I claim as my invention, and desire to secure by Letters Patent,is

I. The two sets or pairs of pawls D D and E E on the lever C,substantially as and for the purpose herein specied.

2. The lever (l, provided with the two pairs of pawls I) l) and E E, andhaving a permanent handle, c, at one end, and a socket for a removablehandle, d, at the. other end, for the purpose set forth.

3. The guides G G, arranged and operating in combination with the pawlsE E, substantially as and for the purpose herein specified.

